Golf swing training machine

ABSTRACT

A golf swing training device, in which a golf club or golf club simulating device is propelled by the arms and hands of a person along a desired arcuate trajectory under an optimal amount of muscular force, maintains the hands of the user on a single optimal plane, while allowing the club to travel on a separate plane through a structure containing a plurality of rotational means allowing all necessary anatomically desireable movements. A movable user platform allows hysteresis in the swing when a user shifts their weight.

PRIOR APPLICATION

This is a continuation-in-part of application Ser. No. 10/334,643, filedDec. 31, 2002, a continuation-in-part of Ser. No. 09/610,552, filed Jul.5, 2000, a continuation-in-part of Ser. No. 09/407,031 filed Sep. 27,1999, a continuation-in-part of Ser. No. 09/238,001 filed Jan. 26, 1999.

FIELD OF THE INVENTION

This invention relates to the practice of the golf swing.

BACKGROUND OF THE INVENTION

In the sport of golf, the ability to control the flight of the ballthrough striking it with a club is directly related to the quality andrepeatability of one's golf swing. Because of the nature of the body,the design of the club and the flight characteristics of the ball theart of golf is complicated and the subject of endless discussion. Toachieve consistent control over the golf ball, one must develop accuracyand consistency in the practice of their golf swing. Not only does thisrequire significant practice, but also the knowledge of the properfundamentals.

The training machines of the prior art, directed to the swinging of agolf club have attempted to create a physical motion reinforcement thatdevelops the correct swing in the practicing individual. Unfortunately,no prior art has sufficiently accounted for the complexities and nuancesof the golf swing and the golfer's anatomy to accomplish this. They havebeen lacking in the geometric theory and consequently in the physicalconstruction. It is essential that a golf swing training device containexactly the plurality and geometry of rotational axes and adjustments asdoes the present invention.

In order to provide the greatest training value, a practice machineshould limit the motion of the swing to the correct motion whileallowing the user to obtain the natural, free moving feel of its properexecution. It is also advantageous to provide adjustable and variableresistance during that motion to further enhance the trainingexperience.

SUMMARY OF THE INVENTION

The principal and secondary objects of this invention are to provide atraining machine for the practice of golf in which a club or clubsimulating implement is propelled along a desired trajectory underforces applied by the arms and hands of the trainee; and to do so byconstraining the movement of the hands and of the sporting implement tooptimal trajectory planes and against adjustable resistance.

These and other valuable objects are achieved by a training device thatis secured to a stationary frame at an adjustable height above groundand provides a structure for holding a golf club, or a golf clubsimulating device which is linked to the frame by an articulatedassembly that keeps the hands of the user within an anatomically optimalplane regardless of the amount and direction of forces applied by theuser. A plurality of rotational axes and unique geometry permit the bodyand club to behave in a manner consistent with the most desireable swingmotion present in a natural golf swing.

Further, the apparatus may also comprise a laterally movable platformupon which the user stands while practicing the swing. The platformallows the user's feet or stance to move away from or toward the targetof the practice swing. This motion allows the natural shifting of weighttypical of a golf swing while preserving the circular motion of thehands relative to the core of the golfer's body. In practice of a realgolf swing, the user's feet are typically anchored while the upper bodyof the golfer shifts away and toward the target. This feature of thepresent invention further increases the fidelity of the practice motionit provides to that of a real golf swing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an isometric view of the first embodiment of the invention;

FIG. 2 is an isometric view of a golf club attachment assembly;

FIG. 3 is an isometric view of a golf club simulating attachmentassembly;

FIG. 4 a-b are isometric views showing rotation of a club rotating aboutaxis D;

FIG. 5 is an isometric view of a hydraulic resistance mechanism;

FIG. 6 is a cross-sectional view of the linking portion of theresistance mechanism;

FIG. 7 a is an isometric view of a model golfer in a backswing position;

FIG. 7 b is an isometric view of a model golfer in a ball addressposition;

FIG. 7 c is an isometric view of a model golfer in a finished swingposition;

FIG. 8 is an isometric view from below the ground plane of a movableplatform;

FIG. 9 a-d are isometric views of a model golfer in a stationary frameof reference;

FIG. 10 a-d are isometric views of a model golfer in a moving frame ofreference;

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Referring now to the drawing, there is shown in FIG. 1, a motiontraining machine specifically adapted to the practice of golf whichcomprises a stationary frame in the form of a vertical column 1 whichcan be either mounted upon a ground surface or attached to a wall orceiling. A frame member 2 projecting horizontally from a side of thecolumn supports a first bearing housing 3 via a pivotal bracket 4. Thebearing housing 3 is engaged by a first shaft 5 which is rotatable abouta first oblique axis A. A receiving tube or sleeve 6 is attached,preferably, to the lower end of the shaft 5. A rotatable L-shaped arm 7is slidably and axially engaged into the receiving tube 6. A secondbearing housing 8 is secured to the distal end of the arm 7. A secondshaft 9 is engaged into the second bearing housing 8. This shaft isrotatable about a second oblique axis B parallel to axis A.

Referring now to FIG. 2, a golf club assembly, slightly disassembled forclarity, comprises a first sleeve 10 connected by a first arcuate member12 to a pair of coaxial sleeves 13. Axis B of the first sleeve 10 isperpendicular to axis C of the second pair of sleeves 13. Asemi-circular member 14 is attached to two shafts 20 that are heldcoaxially in sleeves 13. A semi-circular member 15 is attached near itsmidpoint to the midpoint of the member 14. At one end of thesemi-circular member 15 is attached a sleeve 16. Another sleeve 17 isattached to the opposite end of the member 15. A right-angle pivot pin21 has a first portion attached to the inside top of the sleeve 16 suchthat the axis of the other portion of the pin which is perpendicular tothe first portion is coaxial with the second sleeve 17. A golf club 18is held by a retainer 23 mounted below the grip portion of the club. Theretainer 23 has a hole bored along a third oblique axis D passingthrough the center of the mass 19, i.e., the axis of gravity of the golfclub 18 which extends from a median portion of the club head to thecenter of its butt end. The remote portion of the pin 21 is engaged intothe hole so that the retainer 23 and the club 18 can be rotated aboutaxis D. A threaded insert 24 is fitted into the butt end of the club. Abolt 25 passes through the bearing housing 17 and engages the threadedinsert, thus retaining the club against centrifugal forces duringswinging. The first sleeve 10 can be slidingly and adjusted along theshaft 9 and is locked by a pin 11. The club handle assembly is free torotate about axis B. The lower portion of the assembly, principallycomposed of the club 18, members 14, 15 and their attached componentscan rotate freely about Axis C which is perpendicular to Axis B.Referring now to FIGS. 4 a-b, the club 18 can rotate freely about itsaxis of gravity 19 which is coaxial with Axis D. Axis D is perpendicularto axis C and coplanar with axis B.

Referring back to FIG. 1, the height of the device is adjustable by thesliding connection of the frame member 2 on the vertical column 1. Theinclination angle of the trajectory plane is adjustable at the pivotalbracket 4. The radius that axis B describes about axis A relates to thelength of the user's arms, and is adjustable by the sliding connectionof the arm 7 and receiving tube 6. The user places his handssymmetrically astride the intersection of axes B, C and D on the handleof the golf club. Rotational force applied by the user are transmittedto the arm member 7 without inducing adverse motion in the other axes.The height of the machine, the slant of, and the distance between theaxes A and B are adjusted to match the physical characteristic of theuser. A counterweight 20 is slidably, fixably attached to the receivingtube 6 such that it counter acts the weight of all components rotatingabout axis A such that the user is only aware of the weight of the golfclub.

Referring now to FIG. 3, a golf club simulating assembly comprises afirst sleeve 10 connected by a first arcuate member 12 to a pair ofcoaxial sleeves 13. Axis B of the first sleeve 10 is perpendicular toAxis C of the second pair of sleeves 13. A semi-circular member 26 isattached to two shafts 20 that are held coaxially in sleeves 13. At themidpoint of the member 26 is a bearing housing 27 mounted such that itscentral axis is perpendicular to axis C and in the same plane as axis Bof the first sleeve 10. A shortened golf club shaft 28 is retained inthe bearing housing 27. At one end is a standard golf club grip 29 andat its distal end is a golf club head simulating weight 30. The assemblycomposed of the shaft 28, grip 29 and weight 30 is axially symmetric andrelatively shorter than a standard golf club. It is freely rotatable inthe bearing housing 27. The device of FIG. 3 acts similarly to that inFIG. 2 and has the advantage of being more compact and simpler inconstruction.

FIG. 5 shows a mechanism for providing cyclic resistance to theprogression of the implement along its imposed trajectory, and morespecifically, to the rotation about axis A. A yoke member 33 is slidablyand adjustably engaged into the vertical column 1 to provide heightadjustment for the whole machine. A pivot axle 34 spanning the arms 33A,33B of the yoke can be immobilized by tightening the clamping arm endsof the yoke. Lever 36 is fixedly engaged by the axle 34 about its medianportion. The adjustment of the angular position of the lever inreference to the yoke fulfills the same function as the pivotal bracket4 of the first described embodiment of the invention. The lever 36mounts at one end an elongated bearing housing 37 and a bearing sleeve38 at the opposite end. The axes A and F of the housing 37 and sleeve 38respectively are parallel. Referring to FIG. 6, a cross-sectional viewof the bearing housing 36, 37 shows a first shaft 35 engaged into thelower half of the bearing housing and retained by bearings 47. The firstshaft 35 is attached to a receiving tube 6 in like manner as the shaft 5is attached to a similar receiving tube 6 in FIG. 1. The rotating arm 7attachments are the same as previously described. The shaft 35 has asplined end 35A. A second shaft 39 is coaxially engaged into the tophalf of the bearing housing 37 and is retained by a similar bearings 47.The lower end 39A of the shaft 39 is splined and the upper end isattached to a crank arm 40. A spline coupling 41 slidably connects thefirst and second shafts 35 and 39. A slip ring 42 is fitted around thecoupling 41. Two actuator pins 43 passing through windows 37A in thehousing, and attach to the slip ring 42. The windows are shaped to allowvertical travel of the actuator pins 43. Doing so, disconnects theshafts 35, 39 and allows them to be angularly oriented at variouspositions in relation to each other.

Referring back to FIG. 5, a shaft 52 is retained in the sleeve housing38 and orthogonally mounts a cylindrical clamp 44. A double actinghydraulic cylinder 45 is retained in the clamp 44. The rod of thehydraulic cylinder 45 connects to a bearing sleeve 46. A shaft 49engaged in sleeve 46 projects from the crank arm 40 at a specifieddistance from axis A. A flow control means 50, which comprises a checkvalve and needle valve connected in parallel, is fitted to one port ofthe hydraulic cylinder 45. A plumbing connection 51 is made between theflow control means 50 and the opposite port of the cylinder 45. Thisembodiment resists rotation of the arm 7 about axis A in a cyclicmanner. The preferred medium in the hydraulic cylinder isnon-compressible fluid because it does not provide any spring-likeenergy storage. Rotation of the arm 7 through one revolution willencounter one cycle of resistance where the needle valve portion of theflow control means 50 determines resistance, and one cycle of lessresistance where the needle valve is bypassed through the check valve.This configuration allows a user to repeatedly encounter resistance inone direction of rotation and easily return to a starting point. Bylifting the coupling 41 off the shaft 35 and rotating arm 7 a specifiedamount, then re-establishing the coupling, the location of theresistance cycle can be moved to various locations within the range ofmotion. The number of splines on the end of shaft 35 determines thenumber of resistance positions.

FIGS. 7 a, 7 b and 7 c show a model golfer 56 in three relevantpositions of the golf swing as they would appear using the presentpractice apparatus. In the diagrams of FIGS. 7 a, 7 b and 7 c the arc 54defines the plane of travel of the hands of the user 56. The geometry ofthis arc is defined by the inclination I which is determined and fixedby locking of the pivotal bracket 4. The radius R of the arc 54 followedby the gripped handle of the club is defined by the adjustment of thearm 7 in relation to its receiving tube 6. Axis A passes preferablybetween the shoulders of the user 56 and its height in relation to theground plane 55 is determined by adjustment of the frame member 2 alongthe column 1. The arc 54 and hence the plane of travel of the hands isperpendicular to axis A.

The arc 53 defines the plane of travel of the golf club. It is aprinciple of physics that a tethered object such as the golf club 18,propelled about a fixed axis will tend to describe a circle and hence asingle plane of motion. For this reason, the golf club axis of gravity19 will tend to travel on this plane during a swing. FIG. 7 b shows theaddress and ball impacting position of the model golfer. If the swingwere initiated with the club and the golfer's arms held in such a way toform a single plane, then the arcs 53 and 54 would converge to form asingle plane, containing the hands of the user and the golf club axis ofgravity 19. This would negate the need for the structure and rotationalcapability about axis C shown in FIGS. 1, 2 and 3. In practice this isanatomically undesireable. While the wrists are capable of holding theclub at an angle of 180 degrees with the arms, they perform morenaturally with an angle less than 180 degrees. When a swing is initiatedwith this condition, the club and hands will travel on intersectingplanes to adhere to the principles of physics mentioned above. Becauseof the exactness of axes B, C and D, the hands of the user can travel onthe more inclined plane defined by arc 54 while allowing the completerange of anatomical function and allowing the golf club and its axis ofgravity 19 to travel on a less inclined plane as defined by arc 53.Rotation about axis C permits the naturally changing relationshipbetween the club shaft and the arms. At the address position, the anglebetween axis-D and axis B can be seen to be less than 90 degrees. At theends of the swing seen in FIGS. 7 a, 7 c this angle can be seen to begreater than 90 degrees.

Referring to FIGS. 1 and 7 a-c, the function of the four axes ofrotation can be seen. Rotation about axis A is the gross movement of theswing. Rotation about axis B allows for the cocking of the wrists. Thisaction typically will form a right angle between the club shaft and thearms at the two ends of the swing shown in FIGS. 7 a, 7 c.

Rotation about Axis D allows the rolling of the wrists through typically180 degrees. At address and impact, the wrists are typically neutrallypositioned. When the club is swung backwards, the wrists typically roll90 degrees away from the target and when the club is swung forward, theytypically roll 90 degrees forward. The rolling of the wrists translatesdirectly to the changing angle of the club face. It can be seen in FIG.7 a that the club face has opened 90 degrees and is essentially coplanarwith the club plane of travel. FIG. 7 c shows the club face has closed90 degrees and is essentially coplanar with the club plane of travel.This is done in concert with the wrist cocking motion described before.At the moment of impact, the club face must be square with the intendeddirection of travel to achieve a straight shot, so that the wrist rolland cock are principally 0 degrees, or centered in their range oftravel. FIG. 7 b shows that the club face is essentially perpendicularto the club plane of travel and square with the intended direction ofball travel. The wrists are un-cocked and centered in their range ofrolling motion.

FIG. 8 shows a typical embodiment of a movable platform, as viewed frombelow the ground plane. A base frame 57 has a vertically oriented column58 at one end for attachment of a frame member 2, such as shown inFIG. 1. At the ground level of the base frame 57, two linear shafts 59are attached internally. Four linear bearings 60 are carried on theshafts 59 and attached to a movable platform 61. The movable platform 61allows lateral movement of a user's feet and stance relative to thefixed column 58, allowing a variable relationship between the principleaxis of rotation A and the user's stance.

FIGS. 9 a-10 d show a model golfer 56 standing on a movable platform 61,demonstrating a full swing as viewed through two frames of reference. Inthe figures, R designates the center of rotation of the golfer's swing.S and W are reference locations for the golfer's stance, or feetposition and resulting weight. F designates a fixed line in the frame ofreference. Axis A as shown in FIG. 1 extends into and out of the pageand passes through R, the center of rotation of the golfer.

FIGS. 9 a-d are viewed from a fixed frame of reference with the world,as someone would view the present invention being used. The arc 54,which is the arc of travel of the hands of the golfer, is circularbecause the golfer's center of rotation R is fixed in space. FIG. 9 ashows the golfer at an address position, where their weight W, stance Sand center of rotation R are aligned. As the golfer takes a backswing inFIG. 9 b, the golfer's stance S moves forward with the movable platform61 while their weight W stays in place. FIG. 9 c shows the golfer movingtheir stance S backward in a transitional move. FIG. 9 d shows thecompletion of the swing with the golfer's weight W forward of theirstance S. From this frame of reference, the golfer's hands travel acircular arc 54, their weight W and center of rotation R stay fixedwhile their stance S shifts forward, then backward during their swing,accommodated by the moving platform 61.

FIGS. 10 a-d are viewed from a moving frame of reference with the world,as someone would view the present invention, were they on the movableplatform 61. The curve 62, which is the arc of travel of the hands ofthe golfer, is elliptical in nature because the golfer's center ofrotation R will move laterally in the frame of reference while theyperform a circular motion. It has hysteresis, because the golfer'sswing, has different sequence of events in the backswing and forwardswing. FIG. 10 a shows the golfer at an address position, where theirweight W, stance S and center of rotation R are aligned. As the golfertakes a backswing in FIG. 10 b, the golfer's weight W and center ofrotation R move backward. FIG. 10 c shows the golfer moving his weight Wand center of rotation R forward in a transitional move. FIG. 10 d showsthe completion of the swing with the golfer's weight W forward of theirstance S. From this frame of reference, the golfer's hands travel theelliptical path 62 with hysterisis. Their weight W and center ofrotation R move backward in the backswing, then shift forward for theforward swing.

This feature of the present invention, the laterally moving platform,allows the present invention to mechanically reinforce a preferredelliptical swing path which accommodates the natural shifting of agolfer's weight and center of rotation backward and forward. While doingso, the precise circular geometry of the features shown in FIG. 1remains intact along with the behavior shown in FIGS. 7 a-c, working toreinforce the most desirable swing mechanics. A user's feet move forwardand backward during a practice swing while their center of rotationstays fixed in space. In a real golf swing, the golfer's feet staystationary while their center of rotation shifts backward and forward.This is an inconsequential difference between the present invention anda real golf swing because the user must utilize all of the same musclesand techniques in the same manner to effect a swing with the presentinvention as they would with a golf club in a normal golf swing.

While the preferred embodiments of the invention have been described,modifications can be made and other embodiments may be devised withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

1. A swing training device for practicing the propelling by a person'sarms and hands of a club along a defined, arcuate trajectory of a givenradius, above a ground plane according to a person's given height andarm length, said device comprising: a stationary frame; a first movablestructure pivotable about a fist axis; supported by said frame; a secondmovable structure pivotably attached to said first movable structure,rotatable about a second axis which is substantially parallel to saidfirst axis; a third movable structure pivotably supported by said secondmovable structure, rotatable about a third axis which is substantiallyperpendicular to said second axis; and, means for retaining a club suchthat the club can freely rotate about a fourth axis which issubstantially perpendicular to said third axis.
 2. The device of claim1, which further comprises a simulated club, retained by said means forretaining; wherein said simulated club features a grippable portion,freely rotatable about said fourth axis.
 3. The device of claim 1,wherein said device further comprises means for adjustably resistingmovement of at least one of said structures.
 4. The device of claim 1,wherein said device further comprises means for adjusting the height andslant of said trajectory in reference to said ground plane; and meansfor adjusting the radius of said trajectory.
 5. A swing training devicewhich retains a club by an articulated structure such that the club canrotate about three axes, wherein each axis of rotation penetrates agrippable portion of the club; said articulated structure beingsupported by a movable arm; said movable arm supported by a stationaryframe and rotatable about a fourth axis.
 6. The device of claim 1,wherein said device further comprises a movable user platform.
 7. Thedevice of claim 5, wherein said device further comprises a movable userplatform.